Various communication networks own and control special service telephony numbers, such as “800” type numbers. The communication networks lease the special service numbers to various telephony service customers, such as retail businesses and government entities. On calls placed to the special service numbers, the communication networks translate the numbers into routable telephony numbers using various criteria, such as caller number, time-of-day, customer routing plans, and the like.
These communication networks are individually identified by Carrier Identification Codes (CICs). On many special service calls, the network receiving the call (the originating network) translates the special service number into the CIC for the network that owns the special service number (the owning network). The originating network then routes the call to the owning network based on this CIC. The owning network translates the special service number into a telephone number and processes the telephone number to route the call to the customer who has leased the special service number.
Communication networks also share access nodes. For example, two networks may share a switching system that serves the customers of both networks. These customers often lease special service numbers from the communication networks as well. Thus, the shared access node typically handles a large amount of special service calls.
Overview
In a communication network, a call processing system receives signaling for a call indicating a called number. The system processes the called number to determine a single-network identifier associated with the called number. The system processes the single-network identifier to determine if the single-network identifier identifies another network that is affiliated with the communication network. If the single-network identifier identifies an affiliated network, then the system selects a double-network identifier indicating both the communication network and the affiliated network. The system then transfers response signaling that includes the double-network identifier. In some examples, the communication network routes the call to a shared access node based on the double-network identifier, and the double-network identifier creates a record of the two networks associated with the call, even though the call physically bypasses the affiliated network.